Abstract: A personal electronic device (e.g., a tablet computer) may be configured to wirelessly charge an accessory (e.g., a stylus) through a display face of the device. At least a portion of the display face may be transparent to facilitate display viewing. A wireless charging assembly disposed within the enclosure may include a core having one or more windings disposed thereon, which may be configured to generate a magnetic flux above the display face to couple to the accessory. The core may be a pot core, a modified pot core, or may have another shape, such as a PQ core. The one or more windings may be disposed on one or more posts of a pot core, or additionally or alternatively, may be disposed on another portion of the core. A metallic shield may be disposed about the wireless charging assembly, thereby surrounding multiple sides of the wireless charging assembly.

Abstract: A capacitive power transfer system can include a power transmitter having one or more primary side filter components, a communications modulator, and transmitter capacitive couplers; and a power receiver having receiver capacitive couplers capacitively coupled to the transmitter capacitive couplers, one or more secondary side filter components, and a communication demodulator. The one or more primary side filter components and the one or more secondary side filter components can be selected to provide power amplifier operation at a power delivery frequency and act as a stable gain high pass filter above a communications cutoff frequency that is higher than the power delivery frequency.

Abstract: Implementations described herein provide systems and methods for wireless charging. In one implementation, a base has a planar surface. One or more posts extend from the planar surface of the base to form a core. Each of the one or more posts is formed from a plurality of nanocrystalline sheets. The plurality of nanocrystalline sheets of each of the one or more posts is oriented in planes perpendicular to the planar surface of the base. One or more coils are wound around each of the one or more posts to form coil windings.

Abstract: In a wireless charging system, a transmitter coil of a wireless charger device and a receiver coil of a portable electronic device can operate at either of two different operating frequencies. The low frequency can be in a range from about 300 kHz to about 400 kHz, and the high frequency can be in a range from about 1 MHz to about 2 MHz. To provide efficient charging at both frequencies, the transmitter and receiver coils can be formed from a compound, or multi-stranded, wire.

Abstract: This application relates to a wireless charger with increased efficiency during operation. The wireless charging assembly includes a wireless charger and an electronic device. A transmitter coil in the wireless charger can induct magnetic flux to a receiver coil in the electronic device via a magnetic flux pathway.

Abstract: Implementations described herein provide systems and methods for wireless charging. In one implementation, a portable electronic device comprises a housing, a planar inductor coil, and a ferromagnetic shield. The planar inductor coil is disposed in the housing and comprises a conductive wire wound a plurality of turns about a center point and in increasing radii. The ferromagnetic shield is disposed in the housing and overlaps the planar inductor coil. The ferromagnetic shield comprises a first layer comprising a first plurality of iron-based nanocrystalline ribbons arranged in adjacent rows along a first direction and a second layer comprising a second plurality of iron-based nanocrystalline ribbons overlapping the first layer. The second plurality of iron-based nanocrystalline ribbons is arranged in adjacent rows along a second direction different from the first direction.

Abstract: A wireless power system has a wireless power transmitting device such as a charging puck and a wireless power receiving device such as a wristwatch. The charging puck may have a three-wire cable that is coupled between a connector and a puck housing. The wireless power transmitting device may have a set of four coils or other number of wireless power transmitting coils in the puck housing. A switch may be coupled in series with each of the four coils. Control circuitry in the wireless power transmitting device may activate a subset of the switches to switch a subset of the coils into use in transmitting the wireless power to the wireless power receiving device. The control circuitry may have a main portion in the connector that uses a tone-based encoding scheme or other encoding scheme to transmit switch configuration commands to a secondary portion in the puck housing.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may be a wireless charging mat with one or more coils or may be a wireless charging puck with one or more coils. In some embodiments, the wireless charging puck may have six coils or other number of coils arranged in a ring. The wireless power receiving device may have an elongated magnetic core such as a C-shaped core with pillars at opposing ends. First and second coils may be formed on the pillars and a third coil may be formed between the first and second coils. The coils of the wireless power receiving device such as the first and second coils on the magnetic core may be configured to receive magnetic flux emitted by a pair of the six coils in the wireless charging puck.

Abstract: A personal electronic device (e.g., a tablet computer) may be configured to wirelessly charge an accessory (e.g., a stylus) through a display face of the device. At least a portion of the display face may be transparent to facilitate display viewing. A wireless charging assembly disposed within the enclosure may include a core having one or more windings disposed thereon, which may be configured to generate a magnetic flux above the display face to couple to the accessory. The core may be a pot core, a modified pot core, or may have another shape, such as a PQ core. The one or more windings may be disposed on one or more posts of a pot core, or additionally or alternatively, may be disposed on another portion of the core. A metallic shield may be disposed about the wireless charging assembly, thereby surrounding multiple sides of the wireless charging assembly.

Abstract: This application relates to a wireless charger with increased efficiency during operation. The wireless charging assembly includes a wireless charger and an electronic device. A transmitter coil in the wireless charger can induct magnetic flux to a receiver coil in the electronic device via a magnetic flux pathway.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may be a wireless charging mat or other device with coils for transmitting wireless power signals. The wireless power receiving device may be a cellular telephone or other device with coils for receiving the transmitted wireless power signals. The wireless power receiving device has adjustable rectifier circuitry coupled to a pair of coils. The pair of coils is coupled in series at a node. A transistor is coupled between ground and the node and is controlled by control circuitry. The state of the transistor can be changed to place the adjustable rectifier circuitry in either a first mode of operation in which the adjustable rectifier circuitry forms a full-bridge rectifier or a second mode of operation in which the adjustable rectifier circuitry forms a pair of parallel half-bridge rectifiers.

Abstract: A powered joint having a first joint component and second joint component in which the first joint component has multiple degrees of rotational freedom with respect to the second joint component, the powered joint including one or more power transmission coils associated with the first component; a plurality of power receiving coils associated with the second component; a sensor which determines the orientation of the second component with respect to the first component; and a control circuit for selectively connecting one of the plurality of power receiving coils to a power receiving circuit based on information received from the sensor.

Abstract: A wireless power transmitting device transmits wireless power signals to a wireless power receiving device using an output circuit that includes a wireless power transmitting coil. Measurement circuitry is coupled to the output circuit to help determine whether the wireless power receiving device is present and ready to accept transmission of wireless power. Oscillator circuitry for supplying signals to the output circuitry while making measurements with the measurement circuitry is coupled to the output circuit using an impedance injection network. The impedance injection network includes an inductor and a resistor coupled in series. Control circuitry opens a transistor in the output circuit when making measurements with the measurement circuitry and closes the transistor when transmitting the wireless power signals.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may be a wireless charging mat or other device with coils for transmitting wireless power signals. The wireless power receiving device may be a cellular telephone or other device with coils for receiving the transmitted wireless power signals. The wireless power receiving device has adjustable rectifier circuitry coupled to a pair of coils. The pair of coils is coupled in series at a node. A transistor is coupled between ground and the node and is controlled by control circuitry. The state of the transistor can be changed to place the adjustable rectifier circuitry in either a first mode of operation in which the adjustable rectifier circuitry forms a full-bridge rectifier or a second mode of operation in which the adjustable rectifier circuitry forms a pair of parallel half-bridge rectifiers.

Abstract: An inductive power transfer (IPT) system may include an inductive power transmitter having at least one power transmitting coil that generates an IPT field and an IPT director unit over the inductive power transmitter. The IPT director unit may include a low reluctance element such as a magnetic core configured to direct the IPT field from the inductive power transmitter to an inductive power receiver held in place over the IPT director unit (e.g., by a housing of the IPT director unit). While the IPT director unit directs the IPT field from the inductive power transmitter to the inductive power receiver, a mean direction and density of the IPT field entering the low reluctance element from the inductive power transmitter may be different from the mean direction and density of the IPT field exiting the low reluctance element towards the inductive power receiver.

Abstract: A wireless power transmitting device uses a wireless power transmitting coil to transmit wireless power signals to a wireless power receiving device. The wireless power transmitting coil is located in a housing. The housing has a circular outline and contains one or more magnets that couple to corresponding magnets in the wireless power receiving device to help align a wireless power receiving coil in the wireless power receiving device to the wireless power transmitting coil in the wireless power transmitting device. A circular array of capacitive sensor electrodes is supported by the housing at a location that overlaps the wireless power transmitting coil. Capacitive sensor measurements from the capacitive sensor array are analyzed to determine whether a foreign object such as a coin or paperclip is present between the housing and the wireless power receiving device.

Abstract: In an inductively coupled power transmitter a force detector that detects the presence of a potential device by monitoring forces applied to a surface of the power transmitter and activates the inductively coupled power transmitter upon detection of a potential device. An inductively coupled power transmitter having a proximity detector that detects the presence and location of a potential device by monitoring the proximity of devices to a surface of the power transmitter and activates the inductively coupled power transmitter upon detection of a potential device. The transmitter preferably has one or more detection coils each having an area much greater than that of the transmitter coils for detecting the presence of a potential device.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may be a wireless charging mat or other device with coils for transmitting wireless power signals. The wireless power receiving device may be a cellular telephone or other device with coils for receiving the transmitted wireless power signals. The wireless power receiving device has adjustable rectifier circuitry coupled to a pair of coils. The pair of coils is coupled in series at a node. A transistor is coupled between ground and the node and is controlled by control circuitry. The state of the transistor can be changed to place the adjustable rectifier circuitry in either a first mode of operation in which the adjustable rectifier circuitry forms a full-bridge rectifier or a second mode of operation in which the adjustable rectifier circuitry forms a pair of parallel half-bridge rectifiers.

Abstract: In an inductively coupled power transmitter a force detector that detects the presence of a potential device by monitoring forces applied to a surface of the power transmitter and activates the inductively coupled power transmitter upon detection of a potential device. An inductively coupled power transmitter having a proximity detector that detects the presence and location of a potential device by monitoring the proximity of devices to a surface of the power transmitter and activates the inductively coupled power transmitter upon detection of a potential device. The transmitter preferably has one or more detection coils each having an area much greater than that of the transmitter coils for detecting the presence of a potential device.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may be a wireless charging mat or other device with coils for transmitting wireless power signals. The wireless power receiving device may be a cellular telephone or other device with coils for receiving the transmitted wireless power signals. The wireless power receiving device has adjustable rectifier circuitry coupled to a pair of coils. The pair of coils is coupled in series at a node. A transistor is coupled between ground and the node and is controlled by control circuitry. The state of the transistor can be changed to place the adjustable rectifier circuitry in either a first mode of operation in which the adjustable rectifier circuitry forms a full-bridge rectifier or a second mode of operation in which the adjustable rectifier circuitry forms a pair of parallel half-bridge rectifiers.